Crystalline form IV of linezolid

Abstract

The present invention provides a novel crystalline form of linezolid referred to herein as Form IV as well as methods for the preparation and use of Form IV. The present invention provides pharmaceutical compositions that comprise therapeutically effective amounts of Form IV that can be used to treat patients suffering from gram-positive bacterial infections. Various processes for making crystalline linezolid Form IV are disclosed.

1 . A method of preparing crystalline linezolid characterized by data selected from the group consisting of:
 a) a powder X-ray diffraction pattern with peaks at about 13.5, 18.0, 21.1, 22.2, and 25.4±0.2 degrees 2 theta;   b) an FTIR spectrum with peaks at about 2817, 1335, 1229, 1200, and 662 cm −1 ; and   c) an FTRaman spectrum with peaks at about 2975, 2930, 2865, 1083, and 750 cm −1 -comprising:   d) dissolving linezolid in a polar organic solvent to form a linezolid solution;   e) spray-drying the linezolid solution at a temperature of at least 50° C.   
   
   
       2 . The method of  claim 1  where the dissolving is carried out at room temperature. 
   
   
       3 . The method of  claim 1  where the polar organic solvent is methanol. 
   
   
       4 . The method of  claim 1  where the spray-drying is carried out with nitrogen gas. 
   
   
       5 . A process for preparing crystalline linezolid characterized by data selected from the group consisting of:
 a) a powder X-ray diffraction pattern with peaks at about 13.5, 18.0, 21.1, 22.2, and 25.4±0.2 degrees 2 theta;   b) an FTIR spectrum with peaks at about 2817, 1335, 1229, 1200, and 662 cm −1 ; and   c) an FTRaman spectrum with peaks at about 2975, 2930, 2865, 1083, and 750 cm −1 -comprising heating crystalline Linezolid Form II to a temperature of at least 85° C. for at least one hour.